This is what life might look like on Enceladus

Several weeks ago, researchers identified the missing ingredient for life as we know it on Enceladus, which is dissolved phosphorous. Thus, the circumpolar moon of Saturn presents itself more than ever before as one of the most habitable bodies in the solar system after Earth. But what could this life look like?

Enceladus is one of the favorite targets in the search for extraterrestrial life due to its vast underground ocean likely in contact with its rocky core. Here, tidal dissipation is suspected to lead to hydrothermal activity where microorganisms can thrive. It has now been proven that Enceladus’ ocean contains all the ingredients necessary for life as we know it, namely hydrogen, oxygen, carbon, nitrogen and phosphorus.

So, in short, we don’t know for sure if life actually exists on Enceladus. On the other hand, this small moon with a diameter of 500 km is considered today The most habitable place in the solar system outside Earth. Then a question arises: what would possible extraterrestrial life forms look like?

In 2017, researchers from the University of Oxford tried to answer this question. The article is entitled Darwin’s organisms“, published in International Journal of Astrobiologydetailing how the same models of evolution used to explain life on Earth can be used to predict life on other planets.

Natural selection at work

According to Sam Levine, CEO of biotech startup MelonFrost and former researcher at the University of Oxford, he realizes that life on Enceladus may have evolved a very different biochemistry than what we see on Earth. Besides, she can Not even made of DNA.

However, the scientist remembers that evolutionary biology stands still Regardless of the basic building block on which it is built. ” Darwin, for example, formed his theory of evolution without knowing anything about DNA or the biochemistry of life.He didn’t say. There is only one way to get a complicated life. It is by evolution by natural selection. Thus we can assume that extraterrestrials will also be subject to the same set of evolutionary rules as us on Earth. These entities will then be designed to maximize their relevance and validity Generate as many offspring as possible.

Russian dolls and co

On Earth, these rules apply to all living things, even the simplest bacteria. However, for the development of complex life, other factors must also be taken into account, including cooperation. ” Cooperation is essential to the evolution of life on Earth for anything above a single cellexplains to Newsweek Stuart West, Professor of Zoology at the University of Oxford and co-author of the article. So if we find anything that can be seen with the naked eye, it will involve collaboration on some level.“.

To better illustrate the concept, imagine the human body as a set of nested Russian dolls. Each of us is made up of a group of different organs. Each organ consists of a group of cells that cooperate to help the organ to perform its specific function and each of these cells is directed by genes, cooperating with and cooperating with other genes, etc.

Concretely, at each level, the entities try to maximize the ability of the following entities. For the researcher, One of the most exciting predictions we can make about life [potentiellement complexe] On Enceladus, there could also be a similar kind of hierarchy of overlapping entitiesIn such a structure, all sides can then Collaboration to help an organism make more copies of itself.

Some examples of extraterrestrial organisms

Using these rules of cooperation and self-replication, the researchers were then able to make some predictions about what these organisms might look like. One of the creatures described, dubbed the “Octomite”, looks rather like Tardigrades on steroids. As shown, this creature consists of a hierarchy of entities with compatible evolutionary interests in which each part is able to specialize in a specific task. The animal can also reproduce by budding into smaller, larva-like creatures that swim or fly to start a new life elsewhere.

The illustrations below represent simpler organisms with different levels of complexity. The first is a simple transcription molecule with no apparent design. Such a molecule may or may not undergo the process of natural selection. The second entity is more complex, but still very simple, cell-like. However, such an organism could be subject to natural selection. Finally, the last object appears with many complex parts working together.

Of course, note that the characteristics of any potential life forms on Enceladus would have evolved under a very different set of environmental conditions than we have here on Earth. For example, it is very unlikely that these organisms would have evolved eyes because the oceanic environment of Enceladus absorbs almost no light.